Cancer is a significant cause of morbidity and mortality worldwide. While the standards of care for many different cancer types have greatly improved over the years, current standards of care still fail to meet the need for effective therapies to improve treatment of cancer. The clinical use of immuno-oncology agents targeting cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) and the programmed cell death receptor-1 (PD-1) and its ligand PD-L1, have resulted in improvements over the standard of care in the treatment of many cancer types. While these checkpoint inhibitors have produced improved clinical responses in such certain cancers, durable clinical responses only occur in approximately 10-45% of patients. Moreover, a significant number of tumors are either resistant or become refractory. Epigenetic modifiers such as histone deacetylase inhibitors (HDACi) have been successful in the treatment of some hematologic malignancies, but despite preclinical data demonstrating activity against solid tumors, this result has not translated to the clinic as a monotherapy. Accordingly, there is a need in the art for new therapies, including, for example, combination therapies for the treatment of cancers. Provided herein are solutions to these and other problems in the art.